[Paraview] Suggestion for Storing Colors for a Polygonal Mesh

[David E DeMarle]

The normals array, that is the one that is used by default in shading
by the graphics pipeline and a few other filters, is whatever one is
designated as the active normals via
vtkDataSetAttributes::SetNormals(). I do not think the array's name
matters at all.

You probably do not want to store the color information in the active
vectors array, unless you want filters to treat it like a vector, ie
you want to do things like orient glyphs or trace streamlines with it.

Storing it as the scalars is probably better, especially if it is an
unsigned char array, because VTK will color by the active scalars
array by default if the scalars array happens to be unsigned char
(either one - grayscale - or three - rgb - components wide)

David E DeMarle
Kitware, Inc.
R&D Engineer
28 Corporate Drive
Clifton Park, NY 12065-8662
Phone: 518-371-3971 x109



On Mon, Feb 22, 2010 at 4:35 PM, Michael Jackson
<mike.jackson at bluequartz.net> wrote:
> I am in the early stages of designing a new filter that is supposed to color
> triangles based on their normal where the normal is used as an input to the
> filter and a unique color is output for each triangle.
>
>  My questions are:
 >   Where should I store the color information? As a new set of "Scalars" or
> as Vectors as attribute data for the cells? Also, is there a "Standard" that
> is used to store the Normals for Polygonal data (vtkPolyData)? Are they
> always in an attribute data array called "Normals"? I was thinking I need to
> check first to see if the correct type of normals are included already and
> if not then generate the normals during the filter.
>
> Thanks for any help or suggestions.
> ___________________________________________________________
> Mike Jackson                      www.bluequartz.net
> Principal Software Engineer       mike.jackson at bluequartz.net
> BlueQuartz Software               Dayton, Ohio
>
>
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